The demand for smaller electronics with increased performance and functionality has driven the development of complex, high-density integrated circuits and robust packaging that operate in adverse environments. Scaling of planar integrated circuits (ICs) has resulted in devices with large numbers of thin, patterned conductive films (typically Cu or Al) separated by dielectric layers and interconnected through multiple levels of conductive vias. Recent advances in 3D integration and flexible circuitry have further enhanced performance and functionality of electronic circuits.
As integration and packaging of microelectronic devices has become more complex, the multiscale and dissimilar nature of the constituent materials has led to reliability issues that impair electrical performance of the entire system. Failure of interconnects and conductive pathways due to thermomechanical stress remains a long-standing problem hindering advanced packaging. Loss of conductivity in electronic circuits can occur through mechanisms such as interconnect fracture, conductive pathway delamination, and thin film cracking. These circuit failures degrade functionality, requiring costly replacement of the entire component.
Efforts to restore failures within electronic circuits have focused on two different aspects. In the materials aspect, restoration of conductivity has been investigated using external intervention, in the form of heating or of manual delivery of relatively low conductivity materials to the failure site. In the electronic aspect, self-healing circuits have been investigated using hardware redundancy or delay-insensitive asynchronous logic. These conventional approaches to conductivity restoration in electronic circuits have met with mixed success.
It is desirable to provide a system that autonomously restores conductivity to failed electronic circuit elements such as interconnects and conductive pathways. Preferably such a system would not require control software or manual intervention, and would not impair normal operation of the electronic circuit.